All wheel drive (AWD) disconnect systems are designed to improve fuel efficiency for an all wheel drive vehicle by disconnecting the major rotating driveline components of an AWD driveline assembly when the performance or benefits of the AWD driveline assembly are not needed. The AWD driveline assembly is preferably connected only if it will likely provide a performance benefit, such as to improve the operation of the vehicle in slippery conditions.
The AWD connect/disconnect system may wait until an undesirable event occurs, such as a wheel slip, and then react by commanding the AWD to connect. Other methods exist for determining or predicting when a connected state of the AWD system will be beneficial based on information received from sensors onboard the vehicle. For example, U.S. Pat. No. 8,095,287 to Beechie describes the use of ambient temperatures and windshield wiper sensor information to determine whether to actuate an AWD system. New communication systems and protocols, such as vehicle to vehicle (V2V) communications and vehicle to infrastructure (V2I) communications, also allow a vehicle to receive information from other vehicles or from structures on or near a road.